This invention is directed to thermoplastic compositions comprising an aromatic polycarbonate, and in particular filled thermoplastic polycarbonate compositions having improved mechanical properties.
Polycarbonates are useful in the manufacture of articles and components for a wide range of applications, from automotive parts to electronic appliances. Because of their broad use, particularly in metal replacement applications, such as in automotive applications, there is a need for increased stiffness, reduced coefficient of thermal expansion while maintaining excellent ductility and flow.
One known method of increasing stiffness in polycarbonates is with the addition of mineral fillers, such as talc and mica. A problem with mineral filled polycarbonate compositions and blends of polycarbonate compositions is that mineral filled, specifically talc and/or mica filled, polycarbonate or polycarbonate blends degrade upon processing. As used herein, “degrade” and “degradation” of polycarbonates or polycarbonate blends are known to one skilled in the art and generally refer to a reduction in molecular weight and/or a change for the worse in mechanical or physical properties.
There remains a need to reduce or control the amount of degradation encountered with filled polymeric materials, and to provide filled materials with improved mechanical properties similar to unfilled polycarbonates and polycarbonate blends.